jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include "AbbreviationsMap.h"
8#include "DwarfInfo.h"
9
10#include <AK/LEB128.h>
11#include <AK/MemoryStream.h>
12
13namespace Debug::Dwarf {
14
15AbbreviationsMap::AbbreviationsMap(DwarfInfo const& dwarf_info, u32 offset)
16 : m_dwarf_info(dwarf_info)
17 , m_offset(offset)
18{
19 populate_map().release_value_but_fixme_should_propagate_errors();
20}
21
22ErrorOr<void> AbbreviationsMap::populate_map()
23{
24 FixedMemoryStream abbreviation_stream { m_dwarf_info.abbreviation_data() };
25 TRY(abbreviation_stream.discard(m_offset));
26
27 while (!abbreviation_stream.is_eof()) {
28 size_t abbreviation_code = TRY(abbreviation_stream.read_value<LEB128<size_t>>());
29 // An abbreviation code of 0 marks the end of the
30 // abbreviations for a given compilation unit
31 if (abbreviation_code == 0)
32 break;
33
34 size_t tag = TRY(abbreviation_stream.read_value<LEB128<size_t>>());
35
36 auto has_children = TRY(abbreviation_stream.read_value<u8>());
37
38 AbbreviationEntry abbreviation_entry {};
39 abbreviation_entry.tag = static_cast<EntryTag>(tag);
40 abbreviation_entry.has_children = (has_children == 1);
41
42 AttributeSpecification current_attribute_specification {};
43 do {
44 size_t attribute_value = TRY(abbreviation_stream.read_value<LEB128<size_t>>());
45 size_t form_value = TRY(abbreviation_stream.read_value<LEB128<size_t>>());
46
47 current_attribute_specification.attribute = static_cast<Attribute>(attribute_value);
48 current_attribute_specification.form = static_cast<AttributeDataForm>(form_value);
49
50 if (current_attribute_specification.form == AttributeDataForm::ImplicitConst) {
51 ssize_t data_value = TRY(abbreviation_stream.read_value<LEB128<ssize_t>>());
52 current_attribute_specification.value = data_value;
53 }
54
55 if (current_attribute_specification.attribute != Attribute::None) {
56 abbreviation_entry.attribute_specifications.append(current_attribute_specification);
57 }
58 } while (current_attribute_specification.attribute != Attribute::None || current_attribute_specification.form != AttributeDataForm::None);
59
60 m_entries.set(static_cast<u32>(abbreviation_code), move(abbreviation_entry));
61 }
62
63 return {};
64}
65
66AbbreviationsMap::AbbreviationEntry const* AbbreviationsMap::get(u32 code) const
67{
68 auto it = m_entries.find(code);
69 if (it == m_entries.end()) {
70 return nullptr;
71 }
72 return &it->value;
73}
74
75}